Standard Guide for Installing and Operating Settlement Points for Monitoring Vertical Deformations

Importancia y uso:

5.1 Earthen fills are often constructed as engineered structures, for example, dams, or to support engineered structures, for examples, roads or buildings. The weight of the fill may compress or deform the supporting soil or rock foundation resulting in settlement of the soil throughout and beneath the embankment. Temporary embankments or surcharge fills are constructed to increase the strength and/or reduce the compressibility of foundation soils prior to placement of the actual foundation or structure. The designers often monitor the settlement of the earth structure as a function of time to document the magnitude and rate of settlement, to evaluate the potential for future settlement, or to confirm the effectiveness of the surcharge and the schedule for its removal. The monitoring is performed using settlement points installed prior to or during the embankment construction. A settlement point provides an accessible survey point that settles with a selected soil horizon within or below the embankment. Careful design and installation of the settlement point can isolate the survey point from extraneous sources of movement such as frost-induced heave, compression within the embankment, or volume changes caused by moisture gain or loss.

5.2 Various settlement point designs have been developed by the agencies and practitioners that use them. This standard guide provides designs and procedures that can be referred to in design guidelines, specifications and reports.

5.3 This standard guide is not meant to restrict the use of other equally appropriate designs and procedures for the fabrication, installation, operation, and reading of settlement points to monitor deformations in earthen deposits during and after construction.

Note 2: Notwithstanding the statements on precision and bias contained in this guide, the precision of this guide is dependent on the competence of the personnel performing it and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing. Users of this guide are cautioned that compliance with Practice D3740 does not itself ensure reliable testing. Reliable testing depends on many factors; Practice D3740 provides a means of evaluating some of these factors.

Subcomité:

D18.23

Referida por:

D6286_D6286M-20

Volúmen:

04.09

Número ICS:

93.020 (Earth works. Excavations. Foundation construction. Underground works)

Palabras clave:

monitoring fill placement; field instrumentation; settlement platforms; settlement points; vertical settlement;